The touch screen is also known as “touch screen” or “touch panel”, it is an induction liquid crystal display device which can receive an input signal of contact and the like, when the graphic buttons on the screen are touched, the tactile feedback system can drive a variety of coupling devices according to pre-programmed program, it can be used to replace the mechanical button panel, and create a vivid audio and video effects by a liquid crystal display. According to the working principle of the touch screen and information transmission medium, the types of the touch screen can be divided into resistive type, capacitance induction type, infrared type as well as surface acoustic wave type, the capacitive touch screen is one of the most widely used at present.
The capacitive touch screen functions by using the body's current sensing, when fingers touch the metal layer, the user and the surface of capacitive touch screen cooperatively form a coupling capacitor, so fingers take a small current away from the contact point. The current outflows from the electrodes of the four corners of the capacitive touch respectively, and the current of the four electrodes is proportional to the distance between the finger and the four corners, the controller gets the touch point position by calculating the ratio of the four current accurately.
The most commonly used capacitive touch screen uses one glass solution (OGS) technology, a transparent indium tin oxide (ITO) conductive film and sensor are directly formed on a protective glass, a piece of glass plays a dual role of protecting the glass and touch sensor. However, the conductive material in the integrated touch technology is arranged on the surface of the glass, the conductive material is easily scratched, thereby the capacitive touch screen is damaged and can not be normally used. The mainly material used in the integrated touch technology is indium tin oxide, the mainly material of the indium tin oxide is indium, the cost is high, and the resistance of the indium tin oxide is relatively large when the big size screen is prepared, the sensitivity is poor; and in the production process of the touch screen, bonding the conductive thin film layer is needed, and the glass is bonded, such that the thickness is increased, and a process of bonding the glass is added, the production costs go up.